Systems of the above type which employ a patient's own lungs for oxygenation are described, for example, by M. H. Cass and D. N. Ross in an article entitled "The evolution of a by-pass technique using the lungs as an oxygenator," Guy' Hospital Reports 1959; 108:237-44.
However, since 1958 this system has essentially been forgotten, and different mechanical arrangements for the oxygenation of the blood have been used instead. In these systems the oxygen is either added directly to the blood in the form of bubbles, as described , for example, in U.S. Pat. No. 4,374,088, or it is supplied through a gas-permeable but water-tight membrane, as described, for example, in U.S. Pat. No. 3,612,281. More recently, however, there has been renewed interest in the older system as shown by Andre Bodnar and Donald Nixon Ross, for example, in their article "Bilateral Cardiac Bypass Without an Oxygenator for Coronary Surgery" in Progress in Artificial Organs, 1983.
One difficulty with this system, however, is that no appropriate equipment exists to carry it out, so that those who have attempted to make use of such a system have been compelled to create complicated systems comprising conventional cardiotomy reservoirs, blood pumps, filters and other control equipment. It is therefore an object of the present invention to make possible the use of the aforementioned system, but, with the assistance of very simple, yet nevertheless extremely reliable equipment.